Guinea pig invasion

About 2-3 months ago we had a guinea pig wander into the house (older mobile home actually) and take up residence. We see it every once in a while so we know what the critter is. It hasn't been a problem until a week ago ... now it's decided that our houseplants are part of its menu.

We've put out the usual rat traps and poisons (didn't like the poison idea), but haven't had any luck catching or killing the thing. Sitting quietly and waiting for it to show its furry little head, then blasting it with a shotgun, is something my aunt's been considering half-jokingly (I think).